Oliveira Marciel Teixeira, Medeiros Camila Dias, Frosi Gabriella, Santos Mauro Guida
Departamento de Botânica, Laboratório de Ecofisiologia Vegetal, Universidade Federal de Pernambuco, Recife PE 50670-901, Brasil.
Departamento de Botânica, Laboratório de Ecofisiologia Vegetal, Universidade Federal de Pernambuco, Recife PE 50670-901, Brasil.
Plant Physiol Biochem. 2014 Sep;82:66-75. doi: 10.1016/j.plaphy.2014.05.006. Epub 2014 May 22.
The effects of drought stress and leaf phosphorus (Pi) supply on photosynthetic metabolism in woody tropical species are not known, and given the recent global environmental change models that forecast lower precipitation rates and periods of prolonged drought in tropical areas, this type of study is increasingly important. The effects of controlled drought stress and Pi supply on potted young plants of two woody species, Anadenanthera colubrina (native) and Prosopis juliflora (invasive), were determined by analyzing leaf photosynthetic metabolism, biochemical properties and water potential. In the maximum stress, both species showed higher leaf water potential (Ψl) in the treatment drought +Pi when compared with the respective control -Pi. The native species showed higher gas exchange under drought +Pi than under drought -Pi conditions, while the invasive species showed the same values between drought +Pi and -Pi. Drought affected the photochemical part of photosynthetic machinery more in the invasive species than in the native species. The invasive species showed higher leaf amino acid content and a lower leaf total protein content in both Pi treatments with drought. The two species showed different responses to the leaf Pi supply under water stress for several variables measured. In addition, the strong resilience of leaf gas exchange in the invasive species compared to the native species during the recovery period may be the result of higher efficiency of Pi use. The implications of this behavior for the success of this invasive species in semiarid environments are discussed.
干旱胁迫和叶片磷（Pi）供应对热带木本植物光合代谢的影响尚不清楚，鉴于近期全球环境变化模型预测热带地区降水率降低和干旱期延长，此类研究愈发重要。通过分析叶片光合代谢、生化特性和水势，确定了控制干旱胁迫和Pi供应对两种木本植物盆栽幼苗的影响，这两种植物分别是本土的南美猴耳环（Anadenanthera colubrina）和入侵的牧豆树（Prosopis juliflora）。在最大胁迫下，与各自的对照 -Pi相比，两种植物在干旱 +Pi处理中均表现出更高的叶片水势（Ψl）。本土物种在干旱 +Pi条件下比在干旱 -Pi条件下表现出更高的气体交换，而入侵物种在干旱 +Pi和 -Pi之间表现出相同的值。干旱对入侵物种光合机制光化学部分的影响比对本土物种的影响更大。在两种干旱Pi处理中，入侵物种均表现出较高的叶片氨基酸含量和较低的叶片总蛋白含量。对于所测量的几个变量，两种植物在水分胁迫下对叶片Pi供应表现出不同的响应。此外，在恢复期，入侵物种的叶片气体交换与本土物种相比具有更强的恢复力，这可能是Pi利用效率更高的结果。本文讨论了这种行为对该入侵物种在半干旱环境中成功入侵的影响。
